Sentence examples similar to beak sized from inspiring English sources

-- Olivia Judson, "Stop the Mutants!" Reader Comments: Mutations and evolution may not necessarily be of the slow, incremental sort where beak sizes change over generations.

Strong selection occurred towards smaller beak sizes in G. fortis after the arrival of G. magnirostris, especially after a dry season when food supply was a limiting factor.

A study by Peter R. Grant and B. Rosemary Grant of Princeton University shows the rapid evolution of beak size in one of the finches in response to competition.

For a long time G. fortis ruled the roost, eating both large and small seeds depending on beak size, but in 1982 a breeding population of the large ground finch, G. magnirostris, arrived.

But it was predicted that eventually competition for the larger seeds would put selection pressure on the medium finches toward smaller beak size (because those with smaller beaks would get enough seeds to survive, while those with larger beaks would not).

They find that natural selection happens repeatedly, that finches hybridize and exchange genes rarely, and that they compete for scarce food in times of drought, with the remarkable result that the finch populations today differ significantly in average beak size and shape from those of forty years ago.

Within a population of blue jays, there are differences in beak size.

Fig. 1 Beak size distributions of ground finches (Geospiza) on several Galapagos islands.

In other words, there was selection for increased beak size in this population.

Random genetic changes within the population lead to differences in beak size b.

Changes in the food source lead to random mutations that change beak size c.